$A$ compound gives a positive test with $I_2/NaOH$ and is extracted from benzene by saturated $NaHSO_3$. It may be

Arrange the following in the correct order of the rate of Nucleophilic Addition Reaction $(NAR)$:
$(I) \ HCHO$
$(II) \ CH_3CHO$
$(III) \ p-NO_2-C_6H_4CHO$
$(IV) \ p-CH_3-C_6H_4CHO$

$CH_3COOCH_3 +$ excess $PhMgBr$ $\rightarrow \text{product}$ $\xrightarrow{H^+} X$. The product $X$ is:

The product $(A)$ of the following reaction is:

Rank the following compounds in order of increasing value of the equilibrium constant for hydration,$K_{hyd}$. (smallest value first).
$1$: Cyclobutanone
$2$: Cyclopropanone
$3$: Di-tert-butyl ketone

Identify the compounds $A$ and $B$ involved in the formation of the given aldol product: $A + B \xrightarrow{OH^-} CH_3-CH_2-CH(OH)-CH(CH_3)-CHO$